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Volumn 130, Issue 1, 2008, Pages 74-82

Size-dependent charge collection in junctions containing single-size and multi-size arrays of colloidal CdSe quantum dots

Author keywords

[No Author keywords available]

Indexed keywords

ELECTRICAL CHARACTERISTICS; MARCUS MODELS;

EID: 38349043778     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja076438h     Document Type: Article
Times cited : (57)

References (82)
  • 13
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    • Optical Properties of Semiconductor Nanocrystals
    • Jortner, J, Ratner, M. A, Eds, Blackwell Science Ltd, Malden, MA
    • Norris, D. J.; Bawendi, M. G.; Brus, L. E. Optical Properties of Semiconductor Nanocrystals. In Molecular Electronics; Jortner, J., Ratner, M. A., Eds.; Blackwell Science Ltd.: Malden, MA, 1997; p 281.
    • (1997) Molecular Electronics , pp. 281
    • Norris, D.J.1    Bawendi, M.G.2    Brus, L.E.3
  • 28
    • 38349017530 scopus 로고    scopus 로고
    • Kagan, C. R. Basic Physics of Semiconductor Quantum Dots; Proceedings of the NSF - Conicet Quilmes Nanoscience Workshop, 2003, Quilmes, Provincia de Tucuman, Argentina.
    • Kagan, C. R. Basic Physics of Semiconductor Quantum Dots; Proceedings of the NSF - Conicet Quilmes Nanoscience Workshop, 2003, Quilmes, Provincia de Tucuman, Argentina.
  • 56
    • 38349009765 scopus 로고    scopus 로고
    • The direction of flow of electrons is formally opposite that of current, so, at V > 0, the current flows from EGaIn through the QDs to ITO, and at V < 0, the current flows from ITO through the QDs to EGaIn.
    • The direction of flow of electrons is formally opposite that of current, so, at V > 0, the current flows from EGaIn through the QDs to ITO, and at V < 0, the current flows from ITO through the QDs to EGaIn.
  • 57
    • 38349005473 scopus 로고    scopus 로고
    • Occasionally, when a value of V between +1.0 and +2.0 V was applied, the QD junctions failed: the current density increased suddenly by one or more orders of magnitude. Failure of the devices was probably caused by a build-up of negative charge in the PEDOT:PSS layer; accumulation of negative charge leads to over-reduction and ultimately dielectric break-down.
    • Occasionally, when a value of V between +1.0 and +2.0 V was applied, the QD junctions failed: the current density increased suddenly by one or more orders of magnitude. Failure of the devices was probably caused by a build-up of negative charge in the PEDOT:PSS layer; accumulation of negative charge leads to over-reduction and ultimately dielectric break-down.
  • 59
    • 38349079578 scopus 로고    scopus 로고
    • In Figure 6, the Fermi energies of the electrodes (EGaIn and ITO) are drawn at their levels before thermal equilibration of the population of the electrons in the electrodes occurs. This equilibration results in a more negative (by ∼0.35 eV) Fermi level for EGaIn and a less negative (by ∼0.35 eV) Fermi level for ITO
    • In Figure 6, the Fermi energies of the electrodes (EGaIn and ITO) are drawn at their levels before thermal equilibration of the population of the electrons in the electrodes occurs. This equilibration results in a more negative (by ∼0.35 eV) Fermi level for EGaIn and a less negative (by ∼0.35 eV) Fermi level for ITO.
  • 64
    • 38349009766 scopus 로고    scopus 로고
    • The oxidation potential of the QDs is too high for electrons from the HOMOs of the QDs to recombine with holes from the PEDOT:PSS Figure 6
    • The oxidation potential of the QDs is too high for electrons from the HOMOs of the QDs to recombine with holes from the PEDOT:PSS (Figure 6).
  • 78
    • 0033052782 scopus 로고    scopus 로고
    • It is possible that there is some coupling of the charge annihilation reaction to vibrational modes in the QDs, probably the long optical (LO) phonon (hω, 210 cm-1, the out-of-phase vibration of Cd and Se atoms, but, even if S, 1, this coupling (0.026 eV) is much smaller than that estimated for coupling to vibrations in the polymer [Nirmal, M, Brus, L. E. Acc. Chem. Res. 1999, 32, 407
    • -1), the out-of-phase vibration of Cd and Se atoms - but, even if S = 1, this coupling (0.026 eV) is much smaller than that estimated for coupling to vibrations in the polymer [Nirmal, M.; Brus, L. E. Acc. Chem. Res. 1999, 32, 407].
  • 80
    • 38349069600 scopus 로고    scopus 로고
    • Figure 7 shows that |VON|(SSS) ∼ |V ON|(SML) > |VON|SL, We believe that, for a given |V| < |VON, the greater the resistivity of the array, the fewer electrons present at the interface between the QDs and PEDOT: PSS, and the smaller the Coulomb force that is available to precipitate annihilation of charge. Figure S4 shows that the junction SL is less resistive than SML and SSS
    • ON|, the greater the resistivity of the array, the fewer electrons present at the interface between the QDs and PEDOT: PSS, and the smaller the Coulomb force that is available to precipitate annihilation of charge. Figure S4 shows that the junction SL is less resistive than SML and SSS.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.